/Engine/Source/Runtime/Engine/Classes/Engine/NetworkDelegates.h
Delegate fired when net.ReportSyncLoads is enabled and the replication system has determined which property or object caused the load. This is likely reported after the load itself, since the load can occur while parsing export bunches, but we don't know what property or object refers to the loaded object until the property itself is read.
typedef TMulticastDelegate_OneParam< void, const [FNetSyncLoadReport](API\Runtime\Engine\Engine\FNetSyncLoadReport) & > FOnSyncLoadDetected